Leather-stitching machine



R. H. RUDOLPH.

LEATHER STITCHING MACH|NE..

APPLICATION FILED MAY 22. 1919.

1 ,85 2, 222, PatentedSept. 7, 1920.

J SHEETS-SHEET 1.

WM $5M HH HH HM R. H. RUDOLPH.

LEATHER S T|TCH|NG MACHINE. APPLICATION FILED MAY 22, 1919.

1 352, 222 Patented Sept. 7, 1920.

7 SHEETS-SHEET 2.

R. H. RUDOLPH.

LEATHER STITCHING MACHINE.

APPLICATION FILED MAY 22. I919.

PatentedSept. 7, 1920.

R. H. RUDOLPH.

'LEATHER STITCHING MACHINE.

APPLICATION FILED MAY 22, 1919.

7 SHEETS-SHEET 4- PateIitedSept. 7, 1920.

R. H. RUDOLPH.

LEATHER STITCHING MACHINE.

APPLICATION FILED MAY 22, 1919.

Patented Sept; 7,1920.

TSHEETS-SHEET 5.

R. H. RUDOLPH.

LEATHER STiTCHlNG MACHINE.

APPLICATION FILED MAY 22, I919.

Patented Sept. 7,1920.

7 SHEETS-SHEET 6.

R. H. RUDOLPH.

LEATHER STITCHING MACHINE.

' APPLICATION FILED MAY 22, I9l9. 1,352,222, PatentedSept. 7,1920.

7 TSHEETS-SHEET 7. 1kg 66 llllllilllll/ 'IIIIIIIIIIpFII/Il/ lllllt! do F J9 x I I /////////%1 UNITED STATES serene GFFIQE.

RAYMOND H. RUDOLPH, OF ELGIN, 'JILLINOIS, ASSIGNOR OE 'ONE-HALF TO CHARLI E IS FRIEDMAN, OF CHICAGO, ILLINOIS. I

LEATHER-sme ma. MACHINE.

Specification of Letters Patent. I Patented Sept, 7, 192a Application filed May 22', 1919. I Serial No. 298,969.

To all whom it may concern Be it known that I, RAYMOND H. RUDOLPH,

a citizen of the United States, residing at the city of Elgin, in the county of Kane and State of lllinois, have invented certain new and useful Improvements in Leather- Stitching Machines, of which'the following is a specification. V

This invention relates to new and useful improvements in leather stitching machines such as are used in the manufacture and repair of shoes, harness, etc., and embodies improvements over my former #1,295,070, issued February 18, 1919.

One of the principal objects of this in vention is to provide a machine for the purpose set forth WhlCh isfextremely simple in construction, positive infoperation, and

which is composed of a minimum'number of parts.

Another important object of the inven-.

tion is to provide a bobbin case 'with a tensioning device therefor, which is so; constructed as to permit the same being moved to render the bobbin accessible.

Another object of the IHVQHtIOILlStO proide an intermittently actuated presser foot, the actuating means therefor embodying a very simple construction, whereby a varying amount of pressure may be readily applied to the foot while work is disposed thereunder. l A further obj ect of the invention is to provino a shuttle which cooperates with the under thread, the shuttle rotating about an j work, whereby channel will be formed for rezeiving the upper thread V A still r"urther ob ect of the invention 1s to provide an intermittently actuated lower thread positioning device for causingsaid thread to be positioned relative to the needle,

whereby said needle will, with certainty, engage the thread.

'llhese and other objects will in part be latent,

slot 15.

obvious, andewill hereinafter be more fully explained.

in the drawings, which show by way of illustration, one embodiment of my invention,

chine.

1* 1g. 2 1s. afront elevation thereof.

is a slde elevation of the righthand side of the machine, the driving pulley being removed and the main in sect on. F 451$ aside elevation of the lefthand shaft shown side of the ma'chine.

l ig. is a vertical sectional view taken on the line 5 5 of Fig. 1. "Fig. 6 is a longitudinal sectional View taken on the line 66 of Fig. l. V

v 1 1g. 7 1s a detail sectional View" of the 'presser foot adjustment.

Fig.8 is a detail vertical view taken on thellne 88 of Big. 3.

Fig. 9 is a plan sectional view taken on line '99 of F 1g.- 2, and

Fig. 10 is'a fragmentary view in eleva- Y igure 1 1s a top plan view of the mation SllOWlllgtllG thread loop distended for thejentrance of the shuttle.

Referring to the drawings,.the machine includes. a base 5, and extending upwardly IlGfil the rear portion thereoi'are' spaced standards (36, in which is journaledthe main driving shaft 7 said shaft being driven through the medium of a belt wheel 18, to which isattacheda hand wheel 9. Bolted tothe front end of the base 5 are spaced angle brackets 10 and-11 respectively. Se-, :cured to the bracket 10 and extending forwardly' therefrom, is an arm 12,*and to the front end of this arm is attached an upwardly extending work supporting arm 13,

supports norizontallydisposed which throat plate 14 at its upper end. This throat plate is formed with an elongated V The work is fedacross the throat plate 14b in a d rection parallel with the Cooperating with the work which is supported on the throat plate, is a, presser foot 16. This presser foot is in thcnature of a rocker arm. Thisarin is connected to a secondarm 17 by an integral'hub 16*, which is journaled in thebracket 10, as clearly shown in- Fig. 8. It will thus be seen that 100 axis of the main shaft 7, and consequently the slot 15 has its ma or axis arranged par- L, 1L

allel with sale shal in the hub any upward movement at thelower end of the arm 17 will cause the presser foot 16 to move downwardly on to the work. In order to intermittently operate this presser foot, I have provided a cam disk 18 having a small cam notch 19 in its periphery, the entire peripl cry, with the exception of the cam notch 19, being concentrically arranged with respect to the main shaft 7, to which it is attached. Journaled in the bracket 10, between the arm 17 of tie presser foot and the main shaft 7, is a pivot pin 20. An arm 21 has one end journaled on the pivot 20, and the other end extending under and normallv on aoin with the 381'131161 b a b I of said ram disk 18. An arm 2.13 is also journaled on the pivot thereof extends under a.d slidingly engages the lower end portion of thearm 17. The other end 25 of this arm 23 extends beyond the pivot 20.

An adjusting screw 26 is threaded into the arm 21 at a point directly over the end 25 of the arm 23. It will thus be seen that by adjusting the screw 26 downwardly, the arm 23 will cause the rock arm 17 to be moved upwardly to force the presser foot downwardly. on tothe work, this movement being obtained by forcing the end 25 of the arm 23 away from the arm 21. This, in turn, forces the end 22 of the arm 21 to engage the periphery of the cam disk 18. It will thus be seen that by means of this adjusting screw 26, a varying pressure may be imparted-to thepresser foot. It will also be noted at this time, that once during each cycle the cam notch 19 will coincide with theup-turned end of said arm 21, and thereby relieve the ressure on said arm 21 and consequently remove the pressure from the presser foot.

From the foregoing, it will be seen that the presser foot 16, the hub 16, and the arm 17 all together constitute a rocking frame. It will also be noted that the arms 21 and 23 .are disposed between the arms 17 of the rocking frame and the actuating cam 18. The arms 21 and 23 constitute in effect a toggle connection.

In the drawings, 1 have designated the leather or'other work being sewed by thepresser foot is an awl 27, see particularly Fig.5. This awl carried by an arm 28,

which is rigidly secured to a transverse shaft 29. One end of this shaft is disposed withl6 The arm 28 1s a reel arocating arm and the awl moves from a point below the work support upwardly through to cause the 'awl to positively feed the work a distance equal to thelength of one stitch.

20, and one end 2 fv pressure of the presser foot has been leased. In order .to oscillate the awl about its shaft, said shaft is provided with a rearwardly extendmg rock arm 31, Whlcll is pivotally connected to one end of a link 32. The other end of this link is pivotally connected, as at 83, to one end of a roller arm 34-, which is fulcrumed at 35 to the base 5. above the main shaft '7 and thence downwardly to its pivot 35. A roller 36 is carried by the arm 3%. and operates in a cam groove 37 formed in a cam disk 58 fixed to the main shaft '7'. The camgroove 37 is so shaped that the awl will be held in its retracted or inoperative position for the greater portion of each cycle. it will be noted that the shaft 29 and the awl are disposed in rear of the work support. he cam groove 37 is so shaped as to cause the awl to remain in the work during the feed-- ing action thereof.

In order to shift the shaft 29 endwise against the tension of the spring 30, I have provided a lever 39, which is fulcrumed on the bracket 11 by the screw This lever extends rearwardly and the screw L0 is posed in rear of the shaft 29. The other end of the levercarries a roller ll which is intermittently engaged by the cam plate l2,

The arm 34: extends rearwardly.

fixedly mounted on the side face of the cam disk 43, It will thus be seen that as the cam disk 4:3rotates, the cam plate 12 will,

during each revolution, engage the roller %1,

causing the lever 39 to swing about its pivot is in the work, and while the pressure of the presser foot has been released. The cam plate 42 is of such a length that theroll r 41 w1ll become isengaged therefrom as soon as the feeding stroke of the awl hasbeen completed, thereby permitting the spring to return the shaft 29 to its original position.

After the awl has performe'dits feeding action and has withdrawn, it leaves anopening in the work'in a position to be entered by a needle 44:. This needle is provieed with a hook 453 near its point, and the needle is carried by a holder 45 which is journaled on the shaft 29. The holder {l5 is'provided 'with a. rock arm d6 which, in turn, is pivotally connected,.as at 4:7, to one end of a The other end of the link 48 a link 48.

pivotally connected, as at 4-9, to one end of alever 50. This lever is fulcrumed at its angle to a pivot 51 on the base 15. r The lever 50 1s provided with a short 52, which eX- tends forwardly and under the main shaft 7,

the end of the short arm 52 of this lever is I a roller 53, which engages in a cam groove 54- formed in a cam disk 55, which is fitted to the main shaft 7. Tt will be noted at this point that the position of the roller 53 is diametrically opposed to the position of the roller The cam groove 37' of the awl actuating mechanism, and the cam groove 54 of the needle actuatingmechanism, are of such shapes as to time the awl and the needle, whereby the awl will not leave the work until the point of the needle has entered the opening made by the awl From the foregoing, it will be seen that the cam groove 54, will, through the roller 53, rock the lever 50, and this lever, through the link 48 and rock arm 46, oscillate the needle. The cam groove 54 is so shaped as to give the needle a period of rest while the awl is performing its feeding action.

Cooperating with the hooked needle is a rotary shuttle 56, which is mounted in a shuttle case 57 mounted on the bracket 10, and in a plane above theshaft 29, and also above the path of travel of the needle. This shuttle is rotated by means of a shaft .58

which is journaled in the bracket 10, and this shaft, in turn, carries a gear 59 WlllClllS driven by a gear 59 journaled on a shaft 61.,

Fixed to the ear 60 is a s irocket wheel 62 b V p i which is driven by a sprocket chain 03 from a sprocket wheel 64 fixed to the main shaft 7. Disposed within the shuttle is a bobbin 65. This bobbin is oositioned within a seat l i l 1 (it formed in the outer race of the shuttle. In order to provide a variable tension to the bobbin, and also to permit access thereto,

I have provided a supporting; rod 67 in the upper end of the bracket 10. This rod is held against oscillatory movements by a set screw 68. Rigidly secured to the rod 67 is :1 depending arm 69 having at its lower end 1... A 1,. n1 0" qr 1v t 1 an en u-l gea icat i Mica. iy moun ec within this head is a-pin 71 having its inner end rounded at 0 for engagement with the bobbin 'This pin This provided with' a reduced extension 72 which extends outwardly through the head and forms a resultant shoulder 73. An adgusting screw 74 surrounds the reduced end 12' and is threaded into the ad acent end'of the head 7 O. A 0011 spring (5 18 disposed around the l l" l tv l ll-""3 ltdUCGt em: (-1 ant oemeen tne s 1011 col 1 and the adjusting screw 74. By adjusting the screw 74, more or less'tension may beapplied to the pin 71 A and, consequently, to the bobbin 65. Byreleasing the set screw 68, the arm 69 carrying the pin 71 may be swung to. the right'or left and out of the disposed in a plane parof feed of the work. It that the needle 18C1P1'O-' and the axis of thev rates in a vertical plane at one side of the I shuttle, and that the axis of this needle reciprocation is parallel with the line of feed.

and with the shuttle shaft 58.

It will be noted that when the needle is .in the work and is at the extreme low position, it becomes necessary for the hook 45 of the needle to engage the lower thread eX- tending from the last stitch. To this end, I

have provided a thread positioning device. This device consists of an upwardly extending finger 76, which is carried by .a

vertical shaft 77 journaled in the lower portion of the arm 12. The upper end of" a bevel-gear 79, which meshes with a bevelgear 80, fixed to a horizontal shaft 81, journaled in the bracket 10. Secured to the outer end of the shaft '81 is an arm 82, and to the free end of this arm is pivotally connected one end of a push rod 83. The end of the rod 83 is rigidly connected to another rod 84 by a coupling 85, and the rod 84 is slidably mounted in the upper end of a bracket 86. v The rods 83 and 84 extend rearwardly and are normally held in their rearward position byoa coil spring 87. Secured to one face of the cam disk 55 is a trip plate 88. This trip plate, during each cycle of movement, :strikes the rod 84 and causes said rod 84 and rod 83 to be moved endwisein a forward direction against the-tension of the spring 87. causes the rock arm 82 to oscillate the shaft 81 and thereby oscillate thevertical shaft 77, together with the thread finger 76. The oscillation of this thread finger7 6 causes the lower thread to be positioned relative to the needle, whereby the hook in the needle will, with certainty, engage said thread and lift the same upwardly in a loop -.formation wardly bythe needle'to the shuttle, I have j provided thread pick p arm '89.. This pick up arm is tripoperated and moves. in a vertical plane only. It is disposedin close proximity to the needle and. the rear-end thereof is fulcrumed, as at 90, toone end of an arm'91 which is secured by a bolt 92 to the bracket 10.5 The arm 89 extends" forwardly from the pivot 90 over-the shaft 61 29, and thence forwardly over'said shaft. and terminates at a point directly above the throat plate 14. Fixedly secured'to the shaft 61 is a trip-finger 93,'which'engages a downwardly extending shoulder 94', carried by the thread pickup 89. As the shaft 61 revolves, the trip-finger 93 engages the shoulder '94 and swings thearm 89 upthence downwardly toward the shaft V I returned to their initial positions.

wardly so that the outer end thereof will be in a position between the need e 1-1 and the shuttle point. After the trip-finger 925 has passed beyond the shoulder 94:, the thread pick-up arm 89 will return to its normal position through the action of a coil spring 95-, which is connected at one end to the arm 91, and at its other end to the arm 89. After the needle 44 has moved upwardly and drawn the loop of thread therewith, the pick-up arm 89 is then timed to move upwardly and engage the strand of the loop adjacent the pick-up arm, and elevate said loop to a position above the needle. It will be noted, however, that the other strand of this loop is at this time still engaged with the notch 15 of the needle.

In order to further open this loop of thread and to position it relative to the shuttle, whereby the point of said shuttle will, with certainty, enter said loop, I have provided a thread hook 96, which moves in a horizontal plane only. One end of this hook is fulcrumed on the upper end of the bracket 11 by a screw 97, and the free end of this hook is provided with a notch 98 for engaging the thread. Adjacent the pivot 97 the hook is provided with a trip-finger 99, i

which is engaged by a trip arm 100 fixed to the shaft 61. A 0011 spr1ng10l serves to normally hold the hook in its inoperative position, and against a stop 102 fixed to the bracket 10. After the pick-up arm 89 has positioned the loop of thread in the manner previously described, the thread hook is swung laterally by the trip arm 100 and the trip finger 99, and is caused to engage the strand-of thread held by the notch 15 of the needle 4', and thereby distend said loop and cause the same to be held open and in proper relation to the shuttle, whereby the point thereof will, with certainty, enter said loop.

The shuttle, in its revolution, picks up this loop, and the thread pick-up arm and the thread hook will then be automatic zi lly he shuttle, of course, continues to carry this looper thread around the upper thread which extends from the bobbin, and during this movement of the loop, it necessarily passes under or between the bobbin and the tension pin 71'thereof.

In order to indent the work so as to provide a channel on the upper surface thereof for the reception of the thread, 1 have provid d a trip-actua ed indentor 103,.which is provided with a substantially V-shaped end 104. This indentor is carried by a lever 105 fulcrumedon the shaft 61. This lever is positively operated by a trip-cam 106, and is automatically returned by a spring 107. The parts are so timed that the indentor performs its function while the feeding action ofthe work is at rest, and, of course,

pivoted at 109 to the base 5. The free end of this arm carries a thread eye 110, which,-

in turn, is carried by a shank 111. The shank 111 is slidably fitted into an opening formed in the free end of the arm 108. lhis sliding adjustment permits the thread eye 110to be moved longitudinally of the arm 108, and thereby regulates the amount of pull-up to be given to the lower thread. The shank 111 may be held in adjusted position by a set screw 112. The arm 108 is provided with a rigid angular extension 11 3 which is engaged once during each cycle by a trip arm 11%, which is mounted on the cam disk 13. The lower thread which passes through the thread eye 110 is thence led through a tension 115 to the source of supply. As the needle 14 moves upwardly and carries the loop of lower thread therewith, and while the thread. pick-up arm 89 also moves upwardly to distend the loop of lower thread, the take-up arm 108 is moved upwardly by the action of the thread. After this'loop of thread has been engaged by the shuttle and carried around to a point where it is about ready to pass under the bobbin tension pin 71, the trip plate 114 cooperates with the eXtension'113and causes the 108 to be positively moved in a downward direction, thus not only forcing the loop of thread past the tension pin 71, and oif the shuttle, but also serving to place suilicient tension on the thread to pull up the stitch just completed in a very tight to feed the work and to position the awl opening therein in line with the needle, a rotary shuttle disposed above the plane of the needle and rotating about an axis parallel with the direction of feed of the work, and means cooperating with the needle .to engage the loop of thread carried there by and position the samefor entrance by the shuttle. r i

2. In a lock stitch sewing machine, the

combination of a work support, a reciprocatory 'awl operating from the underside of the work, a longitudinally tensi'oned shaft for supporting the awl, a notched needle operating from the upper side of the work, a cam operated lever engaging one end of the shaft to bodily move the shaft'and awl to feed the work and to position the awl opening therein in line with the needle, a rotary shuttle disposed above the plane of the needle and rotating about an axis parallel with the direction of feed of the work, and separate means disposed above and below the work support cooperating with the needl for respectively lifting and distending the loop of thread carried thereby for the entrance by the shuttle.

In a lock stitch sewing machine, the

combination of a work support, a reciprocatory awl operating from the under side of the work, a longitudinally tensioned shaft for supporting the awl, a'notched needle operating from the upper side of the work, a cam operated lever engaging one end of the shaft to bodily move the shaft and awl to feed the work and to position the awl opening therein in line with the needle, a rotary shuttle disposed above the plane of the needle,and means cooperating with the needle to engage the loop of thread carried thereby and position the same for entrance by the shuttle.

4i. In a lock stitch sewing machine, the combination of a work support, a reciprocatory awl operating from the under side of the work, a longitudinally tensioned shaft for supporting the awl, a notched needle operating from the upper side of the work, a cam operated lever engaging one end of the shaft to bodily move the shaft and awl to feed the work and to position the awl opening therein in line with the needle, a rotary shuttle disposed above theplane of the needle and rotating about an axis parallel with the direction of feed. of the work, an intermittently actuated pick-up arm cooperating with the needle to lift the loop of thread carried thereby to a plane above the needle, and an intermittently actuated thread hook for distending said loop of thread and positioning the same for the entrance by the shuttle.

5. In a lock stitch sewing machine, the combination of a work support, a reciprocatory awl operating from the under side of the work, a longitudinally tensioned shaft for supporting the awl, a notched needle operating from the upper side of the work, a cam operated lever engaging one end of the shaft to bodily move the shaftand awl to feed the work and to position the awl opening therein in line with the needle, a rotary shuttle disposed above the plane of the needle and rotating about an axis parallel with the direction of feed of the work, and separate means respectively operating in vertical and horizontal planes and cothe work, a longitudinally tensioned shaft for supporting the awl, a notched needle operating from the upper side of the work, a cam operated lever engaging one end of the shaft to bodily move the shaft and awl to feed the work and to position the awlopening therein in line with the needle, a rotary shuttle disposed above the plane of the needle and rotating about an axis parallel with the direction of the feed of the work, a rotary shaft arranged in rear of and parallel with the line of feed of the work, means for driving said shaft, a' driving connection between said shaft and said shuttle, and separate means cooperating with the needle and actuated by said rotary shaft for respectively lifting and distending the loop of. thread carried thereby'for the entrance by the shuttle.

7. In a lock stitch sewing machine, the combination of a work support, a reciprocatory awl operating from theunder side of the work, a notched needle operating from the upper side ofthe work, means to bodily move the awl to feed the work 'andto position the awl opening therein in line with the needle, a rotary shuttle disposed above the plane of the needle and rotating about an axis parallel with the direction of the feed of the work, a rotary shaft arranged in rear of and parallel with the line of feed of the work, means for driving said shaft, a driving connection between said shaft and said shuttle, a pick-up arm fulcrume-d to swing in a vertical plane to cooperate with the needle to lift the loop of thread carried thereby to a plane abovethe needle, a thread hook pivoted for swinging movements in a horizontal plane for distending said loop of thread lifted by said pick-up arm and positioning said thread for the entrance by the-shuttle, and means carried by said rotary shaft for intermittently operating said pickup arm and thread hook in succession.

8. In a lock stitch sewing machine, the combination of a work support, a longitudinally tensioned horizontal supporting shaft disposed in rear of said work support, a needleholder fulcrurned on said shaft and carrying a notched needle, said needle entering the work from the upper side thereof, an awl fulcrumed on said shaft and op erating from the under side of the work, a cam operated lever engaging one end of the shaft to bodily move the shaft and awl in a general direction parallel with the axis of said shaft to feed the work and to position the awl opening therein in line with the needle, and a rotary shuttle rotating about an axis arranged above the plane of the needle and parallel with the direction of feed ofthe work.

naled in the shuttle support, means to lock.

against movement, an said supporting rod, a head carried by the lower end of said depending arm, a pin mounted in said head for endwise movement, and normally hearing against the bobbin, a spring within the head for exerting a yieldable pressure of the pin against the bobbin, and means for varying the tension of said spring.

11. In a lock stitch sewing machine, the combination of a shuttle support, a shuttle said supporting rod arm depending from 'journaled in said support, a bobbin disposed within the shuttle, and a depending arm mounted on said shuttle support and carrying a tensioning means for the bobbin, said depending arm being mounted for swinging movements to provide access to the bobbin.

12. In a lock stitch sewing machine, the combination of a work support, a stitch forming mechanism, including a notched needle, meansfor reciprocating said needle,

and a thread positioning lever having an upwardly arched intermediate cam operated portion mounted for oscillatory movements about a horizontal axis to position the thread in cooperative relation to the needle. 7

13. In a lock stitch sewing machine, the

combination of a work support, a stitch forming mechanism, including a notched need e, means for reciprocating said needle, I

a thread positioning device mounted for oscillatory movements about avertical axisto position the thread in cooperative relation to the needle, a bevel-gear movable with said positioning device, a bevel-gear oscillating about a horizontal axis and arranged in mesh with the first mentioned gear, a rock arm movable with said second mentioned bevel gear, yieldable means for normally holding said rock arm in its inoperative position, and intermittent means cooperating with said rock arm for actuating the same against the tension of said yieldable means.

RAYMOND H. RUDOLPH.

Witnesses: v

CHAS. C. TILLMAN,

ANNA BLOMQUIST. 

